The present invention relates to lipid-conjugated polyamide compounds, methods for making them, as well as compositions and methods for their use, such as, for example, in the delivery of biologically active agents to cells.
The discovery of new therapeutic agents having increasingly complex molecular structure has presented new challenges related to how they can be efficiently delivered to targeted sites. For example, recent developments in recombinant DNA technology and human genome characterization have enabled identification of the moleculer origins of many genetic and acquired diseases and construction of appropriate plasmids containing desired genes. However, the efficient delivery of these large and heavily charged constructs, having molecular weights of up to tens of millions of daltons and containing several tens of thousands of negative charges into cells remains a substantial challenge. Studies evaluating the use of neutral and cationic liposome structures as vehicles for the delivery of polynucleotides to cells have met with limited success, as these encapsulated structures are rather large and unstable.
Accordingly, compounds that can be used as effective vehicles for the efficient delivery of large complex agents, such as polynucleotides, to cells would be highly desirable.
The present invention is directed to lipid-conjugated polyamide compounds and compositions thereof that are particularly useful in the delivery of bioactive agents to cells.
Specifically, the present invention provides lipid-conjugated polyamide compounds having the general formula: 
wherein n is an integer selected from 1 to about 48 and m is an integer selected from about 2 to about 48, 
wherein R1 for each monomeric unit,
and Ra are independently selected from the group consisting of a hydrogen atom; a hydroxy group; an amino group; a carboxyl group; a sulfonyl group; -SH; an optionally substituted, branched or straight chain aliphatic group having from about 1 to about 8 carbon atoms in a backbone structure that optionally contains nitrogen, oxygen, sulfur, and phosphorus, wherein said aliphatic group optionally has one or more double or triple bonds; an optionally substituted aryl group having from about 3 to about 12 carbon atoms in a backbone structure that optionally contains nitrogen, oxygen, sulfur, and phosphorus; an optionally substituted arylalkyl group having from about 3 to about 12 carbon atoms in a backbone structure that optionally contains nitrogen, oxygen, sulfur, and phosphorus, wherein the alkyl component of said arylalkyl optionally has one or more double or triple bonds; and a lipid moiety that is optionally bonded to a linker moiety,
wherein R1 is not a hydrogen atom for at least one monomeric unit, wherein Rc is selected from a hydrogen atom; a hydroxy group; an amino group; a hydrazine group; a sulfonyl group; xe2x80x94SH; an optionally substituted, branched or straight chain aliphatic group having from 1 to about 8 carbon atoms in a backbone structure that optionally contains nitrogen, oxygen, sulfur, and phosphorus, wherein said aliphatic group optionally has one or more double or triple bonds; an optionally substituted aryl group having from about 3 to about 12 carbon atoms in a backbone structure that optionally contains nitrogen, oxygen, sulfur, and phosphorus; an optionally substituted arylalkyl group having from about 3 to about 12 carbon atoms in a backbone structure that optionally contains nitrogen, oxygen, sulfur, and phosphorus, wherein the alkyl group of said arylalkyl optionally has one or more double or triple bonds; and a lipid moiety that is optionally bonded to a linker moiety,
wherein when R1, Ra, or Rc is an aryl or arylalkyl group having fewer than about 5 carbon atoms in a backbone structure, said backbone structure further comprises one or more heteroatoms,
wherein W for each monomeric unit is independently selected from an optionally substituted, branched or straight chain divalent moiety having from 1 to about 50 atoms and optionally, one or more double or triple bonds in a backbone that contains carbon and optionally contains nitrogen, oxygen, sulfur, and phosphorus, wherein said optional substitution of W may be a lipid moiety that is optionally bonded to a linker moiety,
wherein said lipid moiety is a hydrophobic or amphipathic moiety selected from the group consisting of:
(i) optionally substituted aryl or arylalkyl moieties having from about 14 to about 50 carbon atoms in a backbone structure that optionally contains nitrogen, oxygen, sulfur, and phosphorus, wherein the alkyl component of said arylalkyl optionally has one or more double or triple bonds; and
(ii) optionally substituted, branched or straight chain aliphatic moieties having from about 10 to about 50 carbon atoms in a backbone structure that optionally contains nitrogen, oxygen, sulfur, and phosphorus, wherein said aliphatic moieties optionally have one or more double or triple bonds, and
wherein at least one of Ra, Rc, W for a single monomeric unit and R1 for a single monomeric unit comprises a lipid moiety optionally bonded to a linker moiety.
The present invention also provides a method of synthesizing lipid-conjugated polyamide compounds, said method comprising:
a) contacting
(1) a lipid reactant, with
(2) an oligomer reactant, wherein said oligomer reactant has the general formula: 
wherein n is an integer selected from 1 to about 48, and m is an integer from about 2 to about 48,
wherein each Ta and Tc is independently selected from a terminal group and a reactive moiety that is capable of further reaction with said lipid reactant,
wherein R1 for each monomeric unit, 
xe2x80x83in said oligomer reactant is selected from the group consisting of a hydrogen atom; a hydroxy group; an amino group; a carboxyl group; a sulfonyl group, xe2x80x94SH; an optionally substituted, branched or straight chain aliphatic group having from 1 to about 8 carbon atoms in a backbone structure that optionally contains nitrogen, oxygen, sulfur, and phosphorus, wherein the aliphatic group optionally has one or more double or triple bonds; an optionally substituted aryl group having from about 3 to about 12 carbon atoms in a backbone structure that optionally contains nitrogen, oxygen, sulfur, and phosphorus; an optionally substituted arylalkyl group having from about 3 to about 12 carbon atoms in a backbone structure that optionally contains nitrogen, oxygen, sulfur, and phosphorus, wherein the alkyl group of said arylalkyl optionally has one or more double or triple bonds; and a reactive moiety that is capable of further reaction with said lipid reactant,
wherein when R1, Ra, or Rc, is an aryl or arylalkyl group having fewer than about 5 carbon atoms in a backbone structure, said backbone structure further comprises one or more heteroatoms,
wherein R1 is not a hydrogen atom for at least one monomeric unit,
wherein W for each monomeric unit is selected from an optionally substituted, branched or straight chain divalent moiety having from 1 to about 50 atoms in a backbone that contains carbon, and optionally contains nitrogen, oxygen, sulfur, and phosphorus, and optionally one or more double or triple bonds, wherein said optional substitution of W may be a reactive moiety that is capable of further reaction with said lipid reactant,
wherein at least one of Ta, Tc, W for a single monomeric unit, or R1 for a single monomeric unit comprises a reactive moiety that is capable of further reaction with said lipid reactant; then
b) reacting said lipid reactant with said oligomer reactant to conjugate the lipid reactant to the oligomer reactant.
In another embodiment, the present invention provides a composition comprising a lipid-conjugated polyamide compound of the present invention and a biologically active agent.
In yet another embodiment, the present invention provides a method for inducing the uptake of a biologically active agent by a cell, said method comprising:
providing a composition comprising an effective amount of a biologically active agent and a lipid-conjugated polyamide compound of the present invention; then
contacting a biological sample with an effective dose of said composition,
wherein said biological sample comprises a cell.
In still another embodiment, the present invention provides a method for inducing the uptake of a biologically active agent by a cell in vivo, said method comprising:
providing a composition comprising an effective amount of a biologically active agent and a lipid-conjugated polyamide compound of the present invention; then
administering an effective dose of said composition to a subject.
In a further embodiment, the present invention provides a method of expressing a gene in a mammal, said method comprising:
administering a polynucleic acid complexed with a lipid-conjugated polyamide compound of the present invention to a mammal,
wherein said polynucleic acid is capable of functionally expressing said gene in said mammal, and
wherein said complex is effective at transfecting said gene into a cell in said mammal.
In another embodiment, the present invention provides a method for substantially inhibiting nuclease-induced polynucleotide degradation, said method comprising:
contacting a polynucleotide with a degradation-inhibiting quantity of a lipid-conjugated polyamide compound, and
introducing the polynucleotide and the lipid-conjugated polyamide compound into a nuclease-containing environment.
In still a further embodiment, the present invention provides a method of making a stable preparation of a polynucleic acid complexed with a delivery vehicle, said method comprising:
a) providing a polynucleic acid in a first liquid carrier as a dilute polynucleic acid solution that is substantially precipitant-free;
b) providing a delivery vehicle-forming compound in a second liquid carrier as a delivery vehicle solution that is substantially precipitant-free;
c) combining said dilute polynucleic acid solution with said delivery vehicle solution to form a dilute preparation of delivery vehicle/polynucleic acid complex; then
d) reducing the volume of said dilute preparation to form a stable preparation of delivery vehicle/polynucleic acid complex,
wherein the concentration of polynucleic acid in said stable preparation is higher than the concentration of polynucleic acid in said dilute polynucleic acid solution, and
wherein said stable preparation is substantially precipitant-free.